Measurement and resonance analysis of the S33(n,α)Si30 cross section at the CERN n_TOF facility in the energy

Abstract

The 33 S(n,α) 30 Si cross section has been measured at the neutron time-of-flight (n_TOF) facility at CERN in the neutron energy range from 10 to 300 keV relative to the 10 B(n,α) 7 Li cross-section standard. Both reactions were measured simultaneously with a set of micromegas detectors. The flight path of 185 m has allowed us to obtain the cross section with high-energy resolution. An accurate description of the resonances has been performed by means of the multilevel multichannel R-matrix code SAMMY. The results show a significantly higher area of the biggest resonance (13.45 keV) than the unique high-resolution (n,α) measurement. The new parametrization of the 13.45-keV resonance is similar to that of the unique transmission measurement. This resonance is a matter of research in neutron-capture therapy. The 33 S(n,α) 30 Si cross section has been studied in previous works because of its role in the production of 36 S in stars, which is currently overproduced in stellar models compared to observations.

The fission experimental programme at the CERN n_TOF facility: status and perspectives

“…Furthermore, different setups based on Micromegas detectors have been used for neutron beam characterisation and monitoring [115], for fission tagging in capture measurements of fissile isotopes (see Sect. 4.5), for (n,α) reaction studies [143] and for the characterisation of the spatial profile of the neutron beam using a recently developed variant with both mesh and anode electrodes segmented into strips [144].…”

Study of the 240Pu(n,f) and 237Np(n,f) reaction cross sections at the new experimental area (EAR2) of the CERN n_TOF facility

“…The experimental programme at n TOF [138,139] is mainly focused on measurements of neutron-induced cross-sections for three main categories of reactions: (i) fission reactions which are important for the development of advanced nuclear systems for nuclear energy production [140], (ii) radiative capture reactions which are of great interest to nuclear astrophysics and for the design and operation of nuclear reactors [141] and (iii) charged particle reactions which are relevant to medical applications [142], such as Boron Neutron Capture Therapy and nuclear astrophysics as well [143].…”